Electric furnace.



M. Snom. ELECRIC FUHNACE.

ATI

' APPL I 1918. v 1,274,719. Patented Aug. 6, 1918 Y l t Y 2 EEEE rs- EEEEE 1.

.UNITED T OFFICE.

MARK SHOELD, OF CHICAGO, ILLINOIS, ASSIGNOR TO ARMOUR FERTILIZER WORKS, F

CHICAGO, ILLINOIS, A CORPORATION 0F NEW JERSEY.

n ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Angl e, rais.

Application filed January 28, 1918. Serial No. 214,055.

- jects being to provide a furnace of this typez which is continuous in operation, and which provides a proper and even distribution of the gaseous ingredients throughout the body of solid material employed, both being at that time subjected to the required degreev of heat, preferably produced electrically, and desirably by one or more electric-arcs disposed outside of the chamber in which the chemical action occurs, so as not to interfere with the feed of the material and to render the electrodes less subject to damage and injury. By employing electric-arcs for this purpose, the heat can be readily and desirably concentrated so as to act upon an intermediate Zone or section only of the column of material passing through the conduit or chamber.

Another feature of the invention is to provide a structure of this general character in which a uniform intermixture of the solid material and gas can be obtained at the same time that it is practically uniformly subf jected to the high degree of heat necessary to bring about the chemical reaction.

Preparatory heating of both ingredient-s, solid and gaseous, previous to their entry into the heat zone constitutes anotherimportant element of the invention, such heating being so brought about that the discharging materials after having traversed `the heat chamber are more or less cooled,` each having surrendered some, if not all of its heat to the other entering, and as yet untreated, element.

In the drawing, forming a part of this specification, I have illustrated several embodiments of the invention all of which are described in detail below.

In these drawings:

= Figure l .is a horizontal section through one form of the furnace;

Fig". 2 is a fragmentary vertlcal section on line 2-2'ofF1g. l;

Figs. 3 and L show 1n horizontaland vert-if lal section respectively a diferent style of the appliance; and

VF ig. 5 depicts la furnace of this general character having an inclined instead of `vertlcal or upright, conduit. or passage for the material to be treated.

Referring first to the form of appliance of Figs. l and :2, it will be noticed that centrally it has a vertical, hollow body 10 of graphite or carbon or other suitable refrac' tory material. providing a vertical conduit or passage 1l down which the body of solid pieces, such as briquets composed of nelydivided carbon, alumina, and a binder,`

I descend bv gravity in a slow but continuous astream. Bear the lower portion of such pas- 'sage or chamber the furnace is provided with one or more gasinlet pipes 12' through which a suitable gas. such as nitrogen, or a nitrogen-containing gas, free from oxidizing elements, is introduced under pressure into the lower section vof such body of briquets. These, at the top of the furnace. are introduced in such a way as to provide a constantly descendingbody without permitting escape of the gas, which passes ott' through its own discharge pipe or pipes, not shown. These features it has been deemed unnecessarvto illustrate, as'pthey are all ,understood in the art. At the lower end of the. furnace.

the chemicallychanged briquets are removed without permitting the escape of gas 1n a manner well known. Thus, we have a body 4 or column of' briquets constantly vertically descending,v and traversing such body we have an upward flow of gas. which. by reason of the vertical disposition oi-.arrangement of the column becomes evenly and uniformly dispersed therethrough in a way to facilitate an efficient operation of the ap pliance.

It is, of course, necessary to heat such mixture to bring about the usual chemical action required. and this done in a limited or circumscribed intermediate section or zone only -of the material. This result is desirably accomplished by a plurality of.

'electric-arcs maintained in theusual way between electrodes. outside. of'the passage butjadjacent to the member l0. onsequen'tly, in a-nfouter annular heat chamber, nor compartment 13 surounding the bodyy I0 I provide such heating means. the outer-wall of the chamber comprising an inner-portion tir Vliningli of carbon vbacked up` with one.

los

` and 16 andan outer metal-shell 1T.

or more walls of heat-insulating bricks 15 g The exactconstruction ot this wall is `of no importance except that itmust be able to 'with- 4stand or resist the high degree of heat employed and prevent escape or material loss of 'such heat.

As is clearly illustrated in Fig. 1, the outer surface of the member- 10 is of octagonal shape and against its alternative flat surfaces at the central or intermediate section only of the furnace, the inner end of four electrodes 18, 18, bear so that they are in direct physical contact with the member 10 and hence readily transmit heat to it. Adjacent to such innereiids of these electrodes, and disposed at right angles thereto, are four other companion electrodes 19, 19', each of which is adapted to establish an arc between itself and its companion electrode 18, all as is clearly shown.l These electrodes extend substantially-radially through the outer wall of the furnace and are suitably connected to an electrical circuit. to maintain the electricarcs in a manner indicated. lt will be perceived that these arcs and electrodes are all in the same horizontal plane and relatively .close together, and since the arcs produce concentrated heat, we have the. conduit or passa je 11 at an intermediate portion raisedto a'high degree of heat suflicient to carry 'out the desired chemical reaction.

The operation of the appliance takes place practically as followsz The briquets travel down the conduit continuously in a solid body and the gas ows inai'ily heated by the upwardly flowing hot` gas which has previously traversed the heataone, so that both of the ingredients, solid and gaseous, are first or preparatively raised in temperature before they enter the hot section of the conduit, thus conserving heat, and tending to concentrate the latter at this liairticular portion of the appliance by reason of the two cool incoming ingredients flowing in opposite directions thereto and tending to bank or hold baclg the heat in the hot-zone.

In Figs.. 3 and -l a somewhat diH'e-rent structure employed, the only dilferencebeing in the, 'way that the heat is produced At the zoneV and transmitted to the interior of the conduit or passage. .In this case, none of the electrodes are indirect Contact with the graphite or carbon body 10, but are close thereto, whereby the heat of the arcs is readily transmitted to the material to be treated. The appliance, as shown, has two pairs of electrodes 20, Q0, and 21, 21, in the same plane, producing arcs adjacent to but on opposite sides of the briquet and gas containing member 10. Below these are. two other pairs of electrodes 22, and 23, 23, producing arcs on opposite sides of the body 10,

vbut angulai'ly olfset with. relation to the other arcs 90 degrees', so that four sides of the member 1U are subjected to the heat of the four arcs, bringing about an adequate raising in temperature of the contents ofthe passage to produce the required chemical reaction.

It is not absolutely essential that the passage or flue through the furnace for the'passage of the briquets and gas shall be vertical, but it may be more or less inclined, as illustrated in Fig. and preferably in all instances. the body ofsolid material is caused to pass through the conduit and heat-zone by reason of the action of gravity.

By those skilled in this art it will be appreciated that the desired advantages are secured by employing an apparatus of this character, that is to say, the gas and briquetsv are uniformly intei'mixed, and in such condition are evenly and adequately heated by electric arcs 0r otherwise, which heating means in no way interposes obstacles to the' proper passage of the material through the furnace. Also the two incoming ingredients are preliminarily heated by material, whether solid or gaseous, which has'already traversed the heat-zone, so that the discharging material is desirably cooled and the incoming material desirably initially heated.

l claim: 1. In a furnace of theV character described,

` the combination of a member having a con-y duit for the passage therethrough of the ma'- terial to be treated, and means to heat the contents of said conduit located externally of said member, said member forming no part of said heating means, substantially as described.

in a furnace of the character described, the combination of a member having aconduit for thel passage therethrough of the ma- .tcrial to be treated. and electricalineaiis to heat the contents of said conduit located'exsubstantially as descrilad."

3. ln a furnace of theI character described,

xthe combination'of a meiiibei havin()` `a conduit for the passage therethrough of the ma-, terial to be treated, and means tok produce one or more Ielectric-arcs to heat the con- Lampe@ tents of saidfpassage, said means being lo-A4 'catedl externally. of and forming no arc with said member, substantially vas described.

.4. Ina furnace of the character described, the combination of a member having .a conduit forthe passage there'through of the material to be treated,'and means to heat an intermediate portion only of the contents of said conduit, said means being locatedeX- ternally of said member, said member form- Qing no part of said heating means, substanmore electric-arcs to heat an intermediate tially as described;

5. In a furnace-of the character described, the 'combination of a member'having Va .con-

duit for the passage therethrough of the materia'l to be'treated, and means located ex ternally' of -said'member' to produce one or portion only of the contents of said passage,

-said member forming no part of said arc 4 producing means, substantially as described.

,6. In-a furnace of'the character described, the combination of 1a member having a vertica-l conduit for the passlng therethrough in oppositel directions of thematerials to be said arc treated, and means located i eirternally of said member to heat an intermediate por.v

tion only of the contents of said conduit, said member forming no part of said heat producing means, substantially as described.

7 In va furnace ofthe character described, the combination of a member having a vertical conduit for 'the'passage therethrough of the material to-be treated, and means to produce one or more electric-arcs located 'externally of lsaid member to heat an intermediate portion only of the contentsrof said4 terial to be treatechand means to produce one or more electric-arcslocated externally tof said member, including one or more velectrodes in contact with -said member, substantially as described.-

MARK SHOELD. 

